I can't see the characters and can't log into the account..

Hello, I have a problem in that I haven't played since 2024. When I log in on the website, I can see my characters, but they just have numerical names. But when I log into the game, the account doesn't even log me in. It shows that the characters are there, but I can't log in. Can someone please advise me what to do about this? All characters were level 80 and the account is premium.

Thank you